348 CARBONIFEROUS LAAIELLIBRANCHIATA. 



Cypricardella is very closely related to Mytilomorpha and Sanguinolites. The 

 former genus is, however, distinguished by its strong keel dividing the shell into 

 two flattened triangular portions, the absence of well-marked posterior lateral 

 teeth, and the relatively small development of the lunule and escutcheon, the 

 almost obsolete anterior end, the pointed, almost terminal, and angularly com- 

 pressed umbones, and the absence of regular concentric grooves and ridges 

 externally. The genus Sanguinolites is even more closely related to Cypri- 

 cardella, but is more transverse, has a stronger diagonal fold or ridge, and a 

 rolled edge to the hinge-plate posteriorly and an entirely different hinge. The 

 escutcheon is without an everted edge, and the concentric ridges and markings 

 fail on the dorsal slope, which is hollowed and often traversed by one or more 

 diagonal lines, and the periostracum is tuberculated. 



Edmondia filigrana, de Koninck, if correctly drawn, is shown to possess a 

 lunule and escutcheon, and therefore cannot be correctly referred to that genus, 

 which possesses neither of those characters. It is of course possible that the 

 artist has committed the error, but if lunule and escutcheon are present the shell 

 would have far greater affinities with Cypricardella than with Edmondia. 



Cypricardella parallela, Phillips, sp. Plate XXXIX, figs. 1 — 7. 



Venus parallela, Phillips, 1836. Geol. Yorks., pt. 2, p. 209, pi. v, fig. 8. 

 Cypricabdia paballela, de Koninck, 1843. Desc. Anim. Foss., p. 97, pi. iii, 



fig. 15. 

 Venus parallela, Morris, 1843. Cat. Brit. Foss., 1st edit., p. 104. 



— Brown, 1849. Illust. Foss. Conch., p. 205, pi. Ixxxiii, figs. 3, 4. 



Cypricardia parallela., d'Orbigny, 1851. Prodrome de paleontol., p. 130. 

 Astaute parallela, de ByckJiolt, 1853. Melanges paleontol., partie ii, p. 119. 

 decurtata, de Byckholt, 1853. Ibid., p. 113, pi. xv, figs. 5, 6. 

 ? — stenosoma, de Byckholt, 1853. Ibid., p. 118, pi. xv, figs. 9, 10. 

 Venus? paballela, Morris, 1854. Cat. Brit. Foss., 2nd edit., p. 231. 

 Astabte paballela, Bir/sby, 1878. Thesaurus Devon ico-Carboniferus, p.. 299. 

 Cypricardia parallela, Biysby, 1878. Ibid., p. 305. 

 Astabte stenosoma, Biysby, 1878. Ibid., p. 301. 



Cypricardella parallela, de KonincJc, 1885. Ann. Mus. d'Hist. Nat. Beige, 



torn, xi, p. 96, pi. xiii, figs. 50, 51. 

 decurtata, de Koninck, 1885. Ibid., p. 94, pi. xxi, figs. 35, 36. 

 ? stenosoma, de Koninck, 1885. Ibid., p. 95, pi. xxi, figs. 24 — 27. 



Cypricaudlv parallela, Etheridye, 1888. Brit. Foss., pt. 1, Pah-eozoic, p. 282. 

 r Vims paballela, GoodcJiild, 1894. Proc. Boy. Phys. Soc. Edinburgh, vol. xii, 



p. 356. 



Specific Characters. — Shell below medium size, subrhomboidal, slightly gibbose, 

 inequilateral. The anterior end is short, moderately deep, excavated above by a 



